细沟向浅沟发育过程中沟道几何形态特征变化规律研究  

Changes of the Channel Geometric Characteristics during the Development of Rills to Shallow Ditches

作　　者：金鑫[1,2] 刘浩楠 宋颖 翟婷 赵振鑫 施文飞 JIN Xin;LIU Hao-nan;SONG Ying;ZHAI Ting;ZHAO Zhen-xin;SHI Wen-fei(Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology,Guilin University of Technology,Guilin 541004,Guangxi,China;Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas,Guilin University of Technology,Guilin 541004,Guangxi,China)

机构地区：[1]桂林理工大学广西环境污染控制理论与技术重点实验室,广西桂林541004 [2]桂林理工大学岩溶地区水污染控制与用水安全保障协同创新中心,广西桂林541004

出　　处：《中国农村水利水电》2022年第12期8-16,共9页China Rural Water and Hydropower

基　　金：国家自然科学基金项目(51369009);广西重点研发计划项目(桂科AB21075007);广西自然科学基金(2021GXNSFAA196055)。

摘　　要：通过对坡面侵蚀过程进行分段观测,获得不同侵蚀阶段的坡面侵蚀沟形态三维扫描数据,分析不同阶段的侵蚀沟道宽、深变化情况,对坡面侵蚀沟道由细沟到浅沟的发育过程进行研究。研究结果表明,在降雨初期,侵蚀沟道的宽度明显大于深度,初期侵蚀沟横断面为宽浅形态;随着降雨历时的增加,侵蚀沟平均深度增加的速度快于平均宽度增加的速度。在细沟向浅沟的发展过程中,先出现宽度突破细沟上限(20 cm)的沟道,且所占比例随降雨历时增加而增加;深度大于20 cm的浅沟出现较晚。沟道发育过程中沟壁侵蚀速率较为稳定,沟底下切侵蚀随沟道深度的增加而减缓,导致在沟道发育过程中出现宽度超出细沟上限而深度达不到浅沟深度下限的过渡期沟道;由于径流主要集中于少数侵蚀沟中,绝大多数细沟不会发育成浅沟,这些细沟或者被吞并,或者长时间保持在缓慢的细沟发育阶段,只有极少数的细沟能够最终发育为浅沟,其最大占比仅为2.3%。浅沟出现后,坡面径流更多地汇集到浅沟,更多的侵蚀集中于浅沟的边壁侵蚀和下切侵蚀,坡面其他位置的细沟侵蚀减弱,造成总体侵蚀速度下降,坡面产沙量减少。The experiment simulated the erosion development process of slopes under natural conditions through multiple precipitation intervals on the slope surface,which fully represented the process from rill to shallow rill.Three-dimensional scanning data of slope erosion gully morphology at different erosion stages were obtained by sectional observation of slope erosion process.According to the change of width and depth of gully at different erosion stages on slope,the development process of gully on slope from rill to shallow gully was studied.The results showed that at the beginning of rainfall,the width of erosion gully was obviously more than the depth,and the cross-section of erosion gully at the beginning was shallow and wide.With the increase in rainfall duration,the average depth of erosion ditch increased rapidly.At the end of the test,the average depth and average depth growth rate of the erosion ditch were more than the average width.During the development of trench to shallow trench,trench with width exceeding the upper limit of trench(20 cm)first appeared,and its proportion increased with the increase in rainfall duration.Shallow ditches with a depth more than 20 cm appeared later than those with a width more than 20 cm.The erosion rate of gully wall was relatively stable during the development of gully.As the soil bulk density increased with the increase in soil depth,the cutting erosion under the ditch slowed down with the increase in ditch depth.This led to the transition period channel in which the width exceeded the upper limit of the rill and the depth does not reach the lower limit of the shallow ditch depth.With the development of erosion process,the number and frequency of ditches in the transition period increased gradually.As the runoff was mainly concentrated in a few erosion ditches,the vast majority of rills would not develop into shallow ditches.These rills were either swallowed or maintained in the slow rill development stage for a long time.In the process of erosion,only a few rills could e

关 键 词：细沟 浅沟 侵蚀过程 侵蚀沟道形态 

分 类 号：TV149[水利工程—水力学及河流动力学] P341[天文地球—水文科学]